For months, a disgruntled dancer once acquainted with Casper Smart has publicly and cuttingly questioned his commitment to Jennifer Lopez. Radar Online breaks down the Twitter war waged by a rug-cutter named Joshua Lee Ayers, who hoofed alongside Smart on the 2010 flick "Step Up 3D" (they were both part of the House of Samurai dance crew, as anyone who caught this cinematic extravaganza already knows).

Since March, Ayers has accused J.Lo's beau of all kinds of things, from stealing dance moves (i.e., the plotline of "Bring It On") to not playing for the superstar's team, a claim he tried to back up by sharing a photo of a shirtless Casper sporting gold lamé hot pants jokingly stuffed with what appears to be a Snapple bottle.

"he a complete ‪#POSER‬and foolin U and all Of @JLo fans...," tweeted Ayers. "The truth is come out soon. And u gonna feel stupid. Lol."

(Note to aspiring trash-talkers: Proper grammar is so important in the dissing game. Trust.)

The official word from the couple's rep (yep, they share a rep now -- Casper has officially arrived): "Casper is not gay," their spokesman tells Radar. "These comments are born from envy and jealousy."

But Ayers' bad-mouthing continues. He also took his bitterness over to In Touch, billing himself as Casper's "former best friend" and labeling him a "great self-promoter" with "questionable" talent.

See, according to Ayers, it was Smart's then-girlfriend who landed him the backup-dancing gig with Lopez, but "he used her to get what he wanted, then left her for J. Lo."

The miffed Ayers then warns, "He's willing to do whatever Jennifer wants as long as it furthers his own career."

J.Lo, 42, hooked up with Smart, 25, last fall, shortly after her marriage to Marc Anthony hit the skids. Since then, they've rarely been apart, with the superstar showering her non-famous squeeze with expensive gifts and promoting him to a choreographer on her tour.

If we were the betting type, we'd put even money on Casper becoming hubby No. 4 once her divorce is finalized.